Waiting for this moment South Korean Baek Sung-kuy, 101, arrives to take part in family reunions with his North Korean family members at a hotel in Sokcho. AP SEOUL — Dozens of elderly South Koreans crossed the heavily fortified border into North Korea on Monday for heart-wrenching meetings with relatives most haven’t seen since they were separated by the turmoil of the Korean War.

The week-long event at North Korea’s Diamond Mountain resort comes as the rival Koreas boost reconciliation efforts amid a diplomatic push to resolve a standoff over North Korea’s drive for a nuclear weapons program that can reliably target the continental United States.

The temporary reunions are highly emotional because most participants are elderly people eager to see their loved ones once more before they die. Most of their families were driven apart during the 1950 -53 Korean War, which ended in a ceasefire, not a peace treaty, leaving the Korean Peninsula still in a technical state of war.

Buses carrying about 90 elderly South Koreans and their family members were moving into the Diamond Mountain resort after crossing into North Korea. Earlier in the morning, the South Koreans, some in wheelchairs and aided by Red Cross workers, had left the buses briefly to enter the South Korean immigration office in the eastern border town of Goseong.

They reunited with their long -lost North Korean relatives on Monday afternoon at the start of a three-day reunion. A separate round of reunions from Friday to Sunday will involve more than 300 other South Koreans, according to Seoul’s Unification Ministry.

Many of the South Korean participants are now into their 70s and 80s, with a 101-year-old man the oldest.

Past reunions have produced powerful images of elderly Koreans crying, embracing and caressing each other. Nearly 20,000 people have participated in 20 rounds of face-to-face reunions since 2000. Another 3,700 exchanged video messages with their North Korean relatives under a short-lived communication program from 2005 to 2007.

No one has had a second chance to see their relatives.

Many of the South Korean participants are war refugees born in North Korea who will be meeting their siblings or the infant children they left behind, many of them now into their 70s and 80s, with a 101-year-old man the oldest.

Park Hong-seo, an 88-year -old Korean War veteran from the southern city of Daegu, said he always wondered whether he’d faced his older brother in battle.

Park learned that his brother died in 1984. At Diamond Mountain, he will meet his North Korean nephew and niece, who are 74 and 69, respectively.

“I want to ask them what his dying wish was and what he said about me,” Park said in a telephone interview last week. “I wonder whether there’s a chance he saw me when I was in Wonsan.”

On their second day, they are scheduled to meet again in the morning and have lunch together in their rooms, the first time for separated families to have such a private meeting since the reunion event started.

They will meet on six occasions lasting about a combined 11 hours during their three -day stay that will end Wednesday.